Modifications to a tbm structure to provide roof support installation

ABSTRACT

A TBM having a cylindrically shaped member located on said TBM just behind the rotating boring head, said member being of similar diameter as said tunnel and comprising sectionalized components so as to be adjustable in diameter, said member having a plurality of steel angle members welded to the surface of the top-most component so as to extend axially along the length of said cylindrically shaped member, said steel angle members forming axially extending receptacles therein.

FIELD OF INVENTION

This invention will be found useful in the boring of tunnels through strata where unstable tunnel roofs conditions occur. It will be advantageous to use this invention in tunnels being bored by fairly large tunnel boring machines (TBM's) which have tunneling capacities exceeding 3 meters. This invention may be most advantageously employed where roof instability is a problem.

Basically this invention involves the removal of any extension parts from the front part of the TBM such as extension fingers on the stabilizer of the TBM and extrusion of tunnel roof lining members against the roof surface of the tunnel as the boring process is being carried out. The tunnel lining members are secured in place at predetermined spacing intervals. These tunnel lining members will be fed into suitable receptacles formed on the TBM just behind the rotating boring head. As the machine gradually advances during the tunnel boring process, the material previously inserted into the receptacles provided for the tunnel lining members is fed out (extruded) to be placed against the roof of the tunnel.

At predetermined distances, roof ribs (bow members) are secured (as soon as possible) in place behind the TBM. This assures that any debris from the tunnel roof which might fall due to roof instability is prevented from falling into the tunnel.

In boring large tunnels through strata of varying density, there is a tendency for the TBM boring head to undergo severe radial displacement as the boring process proceeds. In order to prevent such unwanted movement of the TBM boring head, TBM designers have developed a TBM stabilizing system which prevents the TBM's rotating head from executing non-circular movement (wobble) in boring the tunnel.

The stabilizing section of the TBM is located just behind the rotating boring head and presses against the entire circumferential surface of tunnel just previously bored so as to prevent the “wobble” of the rotating cutting head. The rotating head may weigh several tons and the spalling wheels which press against the tunnel face must not be subjected to any side thrust. This is prevented by the presence of the stabilizing section of the TBM.

TBM's function in a fundamental manner by using the walls of a tunnel just previously bored to be used to supply the force which presses the rotating head against the tunnel face. A pair of shaped wall grippers mounted on the TBM push against the walls of the tunnel and are subsequently used as a stop to press the rotating head against the tunnel face. The resulting force which is developed by the wall grippers which presses the rotating head against the tunnel face is massive. It easily overcomes the stabilizing force produced in the TBM by the stabilizing system which is quite small in comparison to the force generated by the wall grippers.

The diameter of tunnel is determined by the diameter of the rotating head and it fell to the TBM operator to see that any excentric rotation of the tunneling machine head is avoided and thus prevent the wobble of the head during a tunnel boring operation.

BRIEF DESCRIPTION OF THE DRAWINGS

The description of the machine of this invention will be best understood when taken with the following drawings in which:

FIG. 1 shows an illustration of a plan view of the TBM to which this invention has been applied;

FIG. 2 is a sectional elevational view of the TBM shown in FIG. 1;

FIG. 3 is a sectional view taken at Section 3.3 shown in FIG. 2 showing the expanding stabilizer of this invention;

FIG. 4 is a sectional elevational view taken at Section 4.4 of FIG. 2 showing the tunnel wall gripper mechanism of this invention;

FIG. 5 is a representation of the receptacles in the surface of the expanding stabilizer of this invention;

FIG. 6 is a sectional view of the tunneling machine stabilizing member as per this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, FIGS. 1 and 2 show the TBM 10 to which this invention has been applied. The TBM has a frame structure 12 (sometimes referred to as the main beam) on which most components involved in the tunneling operations are mounted.

At the very front of the TBM 10 is mounted a rotating head 14 which carries a series of wheels 16 rotatably mounted in bearings (not shown) for contacting the tunnel face. Wheels 16 are made from a hard substance and have a sharp profile to spall the surface of the tunnel face. The materials selected for the wheels 16 tend to fracture rather than bend when subjected to lateral forces. For this reason, it is imperative that the rotating head 14 remains in the center of the tunnel at all times during a tunnel boring operation.

The rotating head 14 is journalled in a suitable bearing 18 which is securely mounted on frame or main beam 12. This assures that any transverse forces experienced by the rotating head 14 are transferred to the frame 12.

The rotating head is driven by a plurality of drive motors 20 two of which are shown in FIG. 2. The drive motors 20 are supplied with suitable spur gears 22 which engage bull gear 24 which is rigidly attached to rotating head 14.

Rotating wheel 14 is supplied with a series of loading buckets such as 26 which are placed at the periphery of wheel 14 so as to gather the debris or “muck” spalled from the tunnel rock face during its excursion from the bottom position of the wheel 14 to its top-most position on wheel 14. At the top-most position of wheel 14 the bucket such as the one shown as 26 empties the debris or muck previously gathered on the upward excursion of bucket 26 into chute 28 of TBM 10; onto conveyor 30 which is mounted in the TBM 10 inside frame 12. Conveyor 30 removes the debris so obtained to a second conveyor or an awaiting railway car located behind the TBM (not shown).

Mounted on frame 12 just behind the rotating head 14, is a non-rotating stabilizing member 40. Member 40 is more clearly shown in section in FIG. 3. Here the member 40 is shown mounted on frame or main beam 12 by means of sliding joint 42. The sliding joint 42 comprises a mating box like structure which has an inner box 44 and an outer box 46 which is firmly secured to stabilizing member 40. Inner box member 44 is firmly secured to frame 12; in this manner the stabilizing member is confined to translatory movement in a plane fixed by the sliding joint 42. It is noted that the conveyor 30 is shown in the interior of the frame or main beam 12.

It is noted that the exterior diameter of the stabilizing member 40 is adjustable within certain predetermined limits. Upper shell 50 is movable up and down by a pair of actuating piston-cylinders 52 and 54 which are pivotably attached to main beam 12 at pivot points 56 respectively. Actuators 52 and 54 are also pivotably attached to upper shell 50 at pivot points 58 and 60. This permits upper shell to be moved vertically up and down by actuators 52 and 54 with respect to main beam 12. The upper shell 50 is provided with a pair of sliding joints 62 and 64 at the junction of the upper shell 50 and the lower shell 66.

Lower shell 66 is a composite structure having lower side members 68 and 70 being pivotably supported on bottom support member 72 at pivots 74 and 76 respectively. Bottom support member is usually firmly attached to frame 12 and is incapable of any movement. The lower side members 68 and 70 are movable about pivots 74 and 76 by a pair of actuators; thus the diameter of the lower shell 66 is also adjustable within “certain” limits by means of actuators 78 and 80. This allows the upper shell 50 and the lower shell 66 of the stabilizing device 40 to be adjusted (within limits) to accommodate variations in tunnel diameters.

It is noted that in FIG. 3, only 3 drive motors 20 are shown for ease of illustration; there may be more motors driving wheel 24 of TBM 10.

A pair of propulsion actuators 82 and 84 are shown also in FIGS. 1, 2 and 3. The actuators 82 and 84 are pivotably attached to frame 12 at one end thereof and pivotably attached to gripper device 90 more fully described in FIG. 4. Gripper device 90 comprises a pair of actuator cylinders 92 and 94 in which a pair of gripper pistons 96 and 98 are respectively received. A pair of grippers 102 are separately actuated and are mounted on the ends of piston rods 96 and 98 respectively. Grippers 102 are used to contact the walls of the tunnel where it has been driven to provide a reference position for the TBM 10 as well as providing a fulcrum for pushing TBM 10 ahead to engage the tunnel face.

The gripper device 90 is slidably mounted on main beam or frame 12 of TBM 10 so as to slide along on tracks 102 and 104 as boring proceeds.

A pair of steering actuators 108 and 110 are shown to change the angle of beam 12 once the grippers 102 have been deployed against the tunnel walls. Here the actuators 108 and 110 are used to cause movement of the main beam 12 about gripper trunion assembly 100. Most of the steering of the TBM is accomplished by the adjustment of actuators 108 and 110 and adjustment of actuators 96 and 98 on the gripper shoes 102.

A rear support cylinder 112 is shown in FIG. 2 having piston 114 and sliding pad 116 attached thereto to carry the rear of TBM 10 during periods of gripper adjustment.

The TBM as illustrated functions as follows: The TBM of FIG. 1 is shown with driving arms 82 and 84 fully extended. In order to prepare the TBM for future movement rear cylinder 112 is actuated until piston 114 and slider 116 make contact with the tunnel surface. Cylinder 112 is actuated until the desired angle of TBM 10 in the tunnel is achieved. At this time grippers 102 are retracted and propulsion actuators 82 and 84 are withdrawn to pull gripper device 90 ahead on slides 104 to the position in FIG. 2.

At this time grippers 102 are actuated to contact the tunnel walls and grippers 102 are set in their working position. Propulsion cylinders are then actuated to push the rotating head against the tunnel face to continue the boring operation. It is understood that steering devices 108 and 110 have been adjusted to be set at the desired angle of TBM 10 in the tunnel so that the steering of TBM 10 is maintained. Some steering (trim) is obtained through the adjustment of devices 52, 54, 78 and 80 of stabilizer 40.

Stabilizer 40 is supplied with adjustable upper shell 50 and adjustable lower shell 66. The upper shell is movable by actuating actuators 52 and 54 as shown in FIG. 3. Because stabilizing member 40 is so long (maybe 3-4 meters) a second set of actuators may be used in FIG. 2 having pivot points 60.

Mounted on the exterior surface of top shell 50 of stabilizer 40 is a series of longitudinally extending members 130.

Members 130 are usually steel angles and form a series of receptacles 132 on top shell 50 of stabilizer 40. The receptacles 132 in this instance are rectangular in cross section but may be of any desired shape.

In this instance the receptacles 132 are formed by “L” shaped angle members welded or secured to top shell 50 of the stabilizer 40. The shape of the resulting receptacles 132 is dictated by the shape of members 130. The members 130 extend the entire length of the stabilizer 40 thus the receptacles 132 are of the same length as members 130.

In operation the TBM functions as follows. The grippers 102 contact the tunnel walls with the propulsion actuators 82 and 84 retracted as shown in FIG. 2. Great force is exerted on the tunnel walls by the actuation of grippers 102. The actuators 96, 98, 110 and 108 on gripper device 90 are set to orient the TBM in the desired direction. Rotating head 14 is now stabilized for a tunnel boring operation. The members 130 secured to top shell 50 contact the surface of the tunnel with considerable force.

Each receptacle 132 is filled with a “roof support” member 134 which has been previously fed into the receptacles 130 by a laborer on the scene. The roof support members 134 are “extruded” from the receptacles 132 as the TBM 10 moves ahead in the tunnel boring process.

It is important that the members 134 do not form a joint in the tunnel roof as the boring process proceeds but that the roof supporting members 134 form staggered joints in the roof as the TBM moves ahead.

At predetermined intervals depending on the stability exhibited by the tunnel roof, roof supports in the form of tunnel arch members 140 or complete tunnel rings 142 may be installed as to support the extruded tunnel roof members 134 against the surface of the tunnel roof as shown in FIG. 6. These supporting rings 142 should be installed as quickly as possible after the TBM 10 moves ahead.

Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that the modifications and embodiments are intended to be included within the scope of the dependent claims. 

1. A TBM having an axially extending frame, a rotating head, a non-rotating stabilizing device, a propulsion means, and a conveyor extending axially along the length of said TBM, said rotating head being suitably journalled in said stabilizing head for rotation on said TBM in close proximity behind said rotating head, said stabilizing device being mounted on said frame and having the shape of a hollow cylinder such that the stabilizing device has an outer diameter which is substantially equal to the diameter of said rotating head, and said stabilizing device has a plurality of axially extending elongated receptacles formed therein.
 2. A TBM as claimed in claim 1 wherein said receptacles extend substantially the entire length of said stabilizing member.
 3. A TBM as claimed in claim 2 wherein said stabilizing device comprises at least a top and a bottom section of said plurality of receptacles is located in the top section of said stabilizing device.
 4. A TBM as claimed in claim 3 wherein said top and bottom sections of said stabilizing device are slidably connected together at sliding joints to allow the diameter of said stabilizing device to be adjustable within certain predetermined limits.
 5. A TBM as claimed in claim 1 wherein said receptacles are formed by welding a plurality of steel members of a predetermined shape to said stabilizing device.
 6. A TBM as claimed in claim 5 in which said receptacles are of a rectangular cross section and are located at the top of said stabilizing device.
 7. A TBM as claimed in claim 6 wherein said plurality of steel members are steel angles welded to said stabilizing device to extend axially of said TBM.
 8. A TBM for boring a tunnel through strata which is unstable, said TBM comprising: a main beam, a rotatable boring head, a stabilizing member of the type which has rearwardly extending fingers attached thereto, a propulsion device, and a conveyor device, said rotatable boring head being suitably journalled in said TBM for rotation about the longitudinal axis of said TBM, said stabilizing member being modified to form a hollow cylinder in which the rearwardly extending finger members have been removed, said stabilizing member being installed on said TBM and adapted to journal said boring head in close juxtaposition therein, and propulsion device comprising at least a pair of actuating devices mounted on said TBM to engage the walls of said tunnel and push said rotatable boring head against the tunnel face, said conveyor device extending at least the length of said TBM to convey debris created by said rotatable boring head from said rotatable boring head along the length of said TBM, said stabilizing member being further modified by the presence of a plurality of longitudinally extending members secured to said stabilizing member and extending the length of said stabilizing member, said longitudinally extending members forming a plurality of longitudinally extending receptacles therein.
 9. A TBM as claimed in claim 8 wherein said stabilizing member is a hollow cylinder having a series of joints therein to permit the stabilizing member to be adjustable in diameter.
 10. A TBM as claimed in claim 9 wherein said stabilizing member comprises a plurality of sections having a series of longitudinally extending joints interconnecting said sections.
 11. A TBM as claimed in claim 10 where said sections are each interconnected by a joint which allows said stabilizing member to be adjustable in diameter, each section having at least one actuator connected thereto to alter the diameter of said stabilizing member.
 12. A TBM as claimed in claim 10 which has a longitudinal axis, and said stabilizing member is provided with longitudinally extending members which extend parallel to the longitudinal axis of said TBM on the outer surface of said stabilizer member, and the receptacles so formed have a rectangular cross-section. 